1. Field of the Invention
The present invention is related to a rotary combustor, or incinerator, for waste material and, more particularly, to an improvement in windboxes which supply combustion air to a rotary combustor, for preventing clogging of the windboxes by low-melting temperature metals, such as aluminum.
2. Description of the Related Art
Proper disposal of solid waste has become an increasingly serious problem as existing sites for land disposal near capacity and new sites become increasingly difficult to locate while the amount of toxic chemicals, particularly in municipal waste, appears to be increasing. Incineration of combustible solid waste has long been used to reduce the quantity of solid matter needing disposal. One device used for this purpose is a water-cooled rotary combustor which has been used in an increasing number of applications over the last one to two decades. While a rotary combustor is capable of burning most types of combustible waste, ranging from eight-foot long logs to typical kitchen waste, certain problems arise when the waste includes low-melting temperature metals, particularly those used in beverage containers, foil, disposable trays, etc. Thus, municipal solid waste, which includes kitchen waste as well as waste from other sources, contains aluminum in a relatively pure state. The combustion temperature in a rotary combustor reaches well in excess of 660.degree. C., at which pure aluminum melts. Therefore, molten aluminum is formed in the rotary combustor and flows downward, solidifying shortly after leaving the combustor and eventually clogging passageways that provide the air required for combustion.